[Duplicate study on the dietary intake of some metals/metalloids by children in Germany. I. Arsenic and mercury]. / Duplikatstudie zur Aufnahme von einigen Metallen/Metalloiden bei Kindern in Deutschland. Teil I: Arsen und Quecksilber.

The dietary intake of arsenic and mercury by 47 children (aged 5-8 years) living in West-Germany (Duisburg) is reported. Duplicate portions of all food and beverages were obtained on 2 days. Arsenic and mercury were measured by atomic absorption spectrometry under careful quality control. Results of are shown in the following table. [table: see text] Fish was consumed at 3 of 94 sampling days only. The arsenic and mercury intake on days with fish consumption was much higher compared with the other days (median, range): arsenic 8821; 4431-11954; mercury 123.7; 80, 0-167.5 ng/kg b.w. and day. The dietary arsenic and mercury intake was much lower than the FAO/WHO PTWI. For mercury the median intake amounted to 1.7% on days without and to 16.6% on days with fish consumption, for arsenic on days without fish consumption to 5.2% PTWI (only for inorganic arsenic compounds established) and on days with fish consumption (in fish mainly organic arsenic occur) 411% of PTWI. Based on the PTWI our data indicate no health risks for German 5-8-year-old children due to arsenic and mercury dietary intake.

[Duplicate study on the dietary intake of some metals/metalloids by children in Germany. part II. Aluminum, cadmium and lead]. / Duplikatstudie zur alimentären Aufnahme von einigen Metallen/Metalloiden bei Kindern in Deutschland. Teil II: Aluminium, Cadmium und Blei.

The dietary intake of aluminium, cadmium and lead by 47 children (aged 5-8 years) living in West-Germany (Duisburg) is reported. Duplicate portions of all food and beverages were obtained on 2 days. Aluminium, cadmium and lead were measured by atomic absorption spectrometry under careful quality control. Results are shown in the following table. [table: see text] The dietary intake of aluminium was low. The median amounted to 2.9% and the maximum value to 11.2% of the FAO/WHO PTWI. The correspondent data for cadmium were 30.2 and 98.7% and for lead 22.2% and 72.1% respectively.

Cadmium, copper, lead and zinc concentrations in hair and toenails of young children and family members: a follow-up study.

In a follow-up study concentrations of cadmium, copper, lead and zinc (measured by atomic absorption spectrometry) in scalp hair and toenail clippings of 47 children (5-9 years) were compared with previous values (2 years earlier). Family members were also monitored. Twenty-five of the children selected have had either high hair values of Cd, Cu, Pb or low hair Zn concentrations or combinations of these (group A) in the first study. Control group comprised 22 children (B). At the follow-up study, there were no more differences between group A and B. Between the first and follow-up study Cd and Pb levels in hair and toenails of group A children declined (geometric means; hair Cd: 265 vs. 111 ng/g; hair Pb: 10.1 vs. 3.8 micrograms/g; toenail Cd: 720 vs. 335 ng/g; toenail Pb 18.5 vs. 5.8 micrograms/g) and hair Zn values increased (54 vs. 103 micrograms/g). Fathers of exposed children had more Cd and Pb in hair and toenails than fathers of control children (hair Cd: 88 vs. 48 ng/g; hair Pb: 4.4 vs. 1.3 micrograms/g; toenail Cd: 46 vs. 23 ng/g; toenail Pb: 1.3 vs. 0.7 microgram/g). No conclusive findings were obtained for Cu. With respect to heavy metal levels of mothers and brothers and sisters there was no uniform pattern. Children < 5 years of age are especially prone to higher Cd, Pb exposure and to lower Zn status compare with older children.

Single-dose toxicokinetics of aluminum in the rat.

The toxicokinetics of aluminum (Al) in male Wistar rats was studied after single intragastric (IG) doses of 1000 and 12,000 micrograms Al/kg and intravenous (IV) doses of 10, 100, 1000, and 12,000 micrograms Al/kg. Serial blood samples, daily samples of urine and feces as well as brain, liver, kidney, spleen, quadriceps muscle, and femur samples were collected. Al was measured by atomic absorption spectrometry. Al blood profiles after IV doses were adequately described by a two-compartment open model. Al toxicokinetics was dose dependent and appeared to plateau at 12,000 micrograms/kg. At IV doses between 10 and 1000 micrograms/kg the terminal half-life of elimination from whole blood (t1/2 beta) increased from 29.9 +/- 7.8 to 209.3 +/- 32.6 min, and the total body clearance (CL) decreased from 2.45 +/- 0.64 to 0.28 +/- 0.03 ml min-1 kg-1. Following an IV bolus of 10 and 100 micrograms/kg the administered Al was recovered completely from urine (94.4% +/- 9.9% and 98.5% +/- 3.2%). Twenty-nine days after the IV dose of 1000 micrograms/kg daily renal excretion decreased to baseline values while only 55.1% +/- 8.0% of the dose was excreted. Nineteen days after the single IV dose of 1000 micrograms/kg Al accumulated in liver (28.1 +/- 7.7 versus 1.7 +/- 0.5 micrograms/g of control rats) and spleen (72.5 +/- 21.1 versus < 0.4 microgram/g). After the single 1000 micrograms/kg IG dose no absorption of Al was detectable. The IG dose of 12,000 micrograms/kg resulted in a maximum blood Al level of 47.9 +/- 12.4 micrograms/l after 50 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal absorption of aluminium: studies in the isolated perfused rat intestinal preparation.

Aluminium (Al) absorption was studied using an isolated in vitro vascularly perfused rat intestinal preparation. Al was introduced into the lumen as AlCl3, Al(NO3)3 or Al lactate to give final concentrations equivalent to 0.625, 1.25, 2.50, 5.00, or 10.00 g/L of Al. The intestinal tissue remained viable up to 5.0 g/L of Al. The amount of Al associated with intestinal tissue after 90 min increased with the concentration up to 5 g/L of Al for chloride and nitrate and 10 g/L of Al for lactate. The time course of Al disappearance from the lumen followed a single exponential decay when the intestinal lumen was perfused with 0.625 g/L of Al as the chloride salt. The total amount of Al appearing in the vascular perfusate after 90 min was always small. Absorption quotes ranged between 0.005-3.2% depending on the salt and concentration used. Addition of transferrin to the VM caused a 2-fold increase in the amount of Al appearing in the vascular effluent in comparison with controls when 1.25 g/L of Al as AlCl3 was introduced into the lumen. Al tissue content was not affected.

Monitoring of cadmium, copper, lead and zinc status in young children using toenails: comparison with scalp hair.

Cadmium, copper, lead and zinc concentrations were determined (atomic absorption spectrometry) in the proximal end of scalp hair (n = 474) and in toenail clippings (n = 461) of children, aged 3-7 years, living in an industrialized and in a rural area of the Federal Republic of Germany. With the exception of Zn in hair, levels of the elements were log-normally distributed. Data are presented as geometric means. Toenail Cd and Pb levels were much higher than those in hair (Cd, 457 vs 90 ng g-1; Pb, 8.5 vs 2.7 micrograms g-1), while Cu and Zn values were similar in both biological media (toenail vs hair: Cu, 7.5 vs 10.6 micrograms g-1; Zn, 129 vs 108 micrograms g-1). In toenails, all elements were positively correlated with each other. In hair, there was a close relationship only between Cd and Pb; Cd and Pb were inversely related to Zn. With the exception of Zn (no correlation), there was a minor relationship between metal levels in hair and those in toenails. Using stepwise regression analysis, seasonal variation was found to be the main factor influencing hair metal levels, while nail metal levels were mainly influenced by place of residence (with the exception of Cu concentrations, for which there were no significant predictors). Multiple correlation coefficient was higher for hair than for nails. It is concluded that, for biological monitoring, toenail clippings are less suitable than hair samples.

Influence of storage conditions on aluminum concentrations in serum, dialysis fluid, urine, and tap water.

The influence of storage temperature, vessel type, and treatment on alterations of aluminum (Al) concentrations in serum, urine, and dialysis fluid samples was studied at three different concentrations for each sample over an 18-month period. Furthermore, the influence of acidification on Al levels in tap water, urine, and dialysis fluid samples was studied over a four-month period. Al was measured by atomic absorption spectrometry. Sample storage in glass vessels was unsuitable, whereas only minor alterations of Al levels were observed with storage in polypropylene tubes, polystyrene tubes, and Monovettes. By using appropriate plastic containers, acid washing of the vessels showed no improvement. Frozen storage was superior compared with 4 degrees C, whereas storage at -80 degrees C offered no advantage compared with storage at -20 degrees C. Acidification of tap water samples was necessary to stabilize Al levels during storage. No striking effect of acidification on Al levels in urine and dialysis fluid samples was found. It is concluded that longterm storage of serum, urine, tap water, and dialysis fluid samples is possible if appropriate conditions are used.

Cadmium, copper, lead, and zinc concentrations in human scalp and pubic hair.

Cadmium, Cu, Pb, and Zn concentrations were measured in the first 3 cm of the proximal end of scalp hair and in pubic hair of 41 humans, by atomic absorption spectrometry. Data are presented as geometric means. Scalp hair (SH) metal levels were higher than those in pubic hair (PH), (Cd, 85.1 vs 60.8 ng g-1; Cu, 17.7 vs 11.9 micrograms g-1; Pb, 1.72 vs 1.05 micrograms g-1; Zn, 148.8 vs 133.3 micrograms g-1) with correlation coefficients of: Cd, r = 0.474; Cu, r = 0.549; Pb, r = 0.576; and Zn, r = 0.263. Further correlations were established between Cd and Pb levels (SH, r = 0.691; PH, r = 0.621) as well as between Cd and Zn levels (SH, r = -0.268). In PH the Cd, Cu, and Pb levels of males were higher than those of females, whereas the Zn levels were lower in SH and PH of males. Scalp hair Zn contents were inversely related to age. Cadmium and Pb levels in SH and PH were higher in summer than in winter, whereas the SH Zn contents were higher in winter. An influence of place of residence, smoking habit, hair colour and hair structure on SH and PH metal levels is identified. It is concluded that hair metal analysis in samples close to the scalp is not seriously invalidated by sources of external contamination.

Hair lead levels in young children from the F.R.G.

Hair lead (PbH) levels were measured in 474 children, aged 3-7 years, living in an industrialized (Duisburg) and in a rural area (Westphalia) of the F.R.G. by atomic absorption spectrometry. PbH values were log-normally distributed. All mean concentrations are therefore given as geometric means. The overall mean PbH content was 2.7 mg/kg. In the summer PbH levels were higher than in the winter (3.8 vs. 1.4 mg/kg) and the values from the urban children were higher compared with those from rural children (3.7 vs. 1.9 mg/kg). Boys had more Pb in their hair than girls (3.9 vs. 2.0 mg/kg) and PbH levels decreased between the 4th and 7th year. In the industrialized area the PbH content of children whose fathers were factory workers, was higher than that of children whose fathers had other occupations (4.2 vs. 3.0 mg/kg). Non-German children had more Pb in their hair than German children (5.2 vs. 3.6 mg/kg). Pb content in the soil from the Duisburg area was related to PbH concentrations (R = 0.34). Since our observations are in line with the results of similar studies which used blood samples to monitor Pb exposure in children, we conclude that by using standardized conditions hair analysis is a valuable screening method.

Calcium alginate, an aluminum-free phosphate binder, in patients on CAPD.

Since dialysis solutions in CAPD are now nearly aluminum free, the only source for elevated aluminum levels are aluminum-containing phosphate binders. Elimination with CAPD is insufficient to prevent aluminum accumulation. Therefore, we investigated a phosphate binder consisting of calcium alginate, a natural polyuronic acid, containing 100 mg calcium/g substance in 14 patients on CAPD over a period of one year. The patients had previously been treated with aluminum-containing phosphate binders for a period of 24.3 +/- 21.3 months. During a period of 3 weeks before changing to the new phosphate binder the mean (+/- SD) serum phosphorus concentration was 1.8 +/- 0.4 mmol/l, while at the end of one year of treatment with calcium alginate the concentration was 1.6 +/- 0.4 mmol/l. In order to lower serum phosphorus to this level, it was necessary to increase the mean (+/- SD) amount of calcium alginate from 6.9 +/- 1.3 g per day at the beginning of the study to 8.3 +/- 2.1 g per day at the end. The mean (+/- SD) serum calcium concentration did not change throughout the study period. Serum levels of alkaline phosphatase, 1.25 (OH)2 vitamin D3, and intact parathyroid hormone did not change as well. The mean (+/- SD) serum aluminum level declined from 36.0 +/- 20 to 14.0 +/- 11.3 micrograms/l after 6 months (p less than 0.001). In conclusion, calcium alginate is a good alternative to aluminum-containing phosphate binders and to phosphate binders on a calcium base as it does not lead to hypercalcemia. It prevents aluminum intoxication and has no serious side effects.

Renal aluminum excretion.

Urinary aluminum (Al) excretion was studied in humans with normal and impaired renal function. Al was measured by atomic absorption spectrometry. In healthy volunteers (n = 50), renal Al excretion was 12.2 +/- 8.5 micrograms/24 h. Two patients on plasma exchange therapy with normal renal function and an inadvertent load of 870 and 388 micrograms Al/treatment showed a 23 and 14% positive balance until next treatment. The renal pathway of excretion was shown to be important in 6 chronic renal failure patients on continuous peritoneal dialysis with residual renal function who eliminated in 24 h 51.4 +/- 24.0 micrograms Al by urine and only 27.2 +/- 18.4 micrograms Al across the peritoneum following a daily oral application of 342 mg Al. Studies with the isolated perfused rat kidney confirmed the limited renal capacity to eliminate Al. Al clearance declined from 0.75 to less than 0.08 mL/min when the kidney was perfused with 0.04-12.4 micrograms Al/mL medium. Al content of the kidney increased in a dose-dependent manner from less than 0.05 to 4.4 micrograms/kidney and reached saturation at 5 micrograms Al/mL medium.

[Chronic aluminum poisoning in continuous ambulatory peritoneal dialysis: treatment with deferoxamine]. / Chronische Aluminium-Intoxikation bei kontinuierlicher ambulanter Peritonealdialyse. Therapie mit Deferoxamin.

After six years of home haemodialysis and two years of continuous ambulatory peritoneal dialysis a 59-year-old woman developed an aluminium-induced osteopathy, myopathy and normochromic anaemia. She was at first treated with intravenous, then peritoneal, deferoxamine, 1 g every other day. Before treatment, 15.8 micrograms aluminium (Al) had been eliminated daily, with a peritoneal clearance of 0.3 ml/min; after intravenous deferoxamine a mean of 774.3 +/- 102.3 micrograms Al was eliminated per day, after peritoneal deferoxamine 646.7 +/- 89.6 micrograms of Al per day, with a peritoneal clearance of 2.2 +/- 0.9 (intravenous) and 1.9 +/- 0.7 ml/min (intraperitoneal). After four months of deferoxamine administration, mostly intraperitoneally as an out-patient, the osteomalacia clearly improved, as did the myopathy and anaemia.

Uptake of aluminum, cadmium, copper, lead, and zinc by human scalp hair and elution of the adsorbed metals.

Uptake of aluminum (Al), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) from aqueous solutions by human scalp hair (water/hair = 100:1) has been studied in the concentration range 0-50 mg/L. Hair metal levels were determined by a wet digestion procedure and atomic absorption spectrometry. Under conditions used, uptake followed a sigmoid concentration-response relationship. The order of binding capacity of hair to the metals was as follows: Al greater than Cd greater than Cu greater than Pb greater than Zn. Using logit transformation 50% saturation was evaluated at the following metal concentrations (hair metal concentration of saturation is given in parenthesis): 0.34 mg/L for Al (0.154 mg/g); 1.82 mg/L for Cd (0.363 mg/g); 2.21 mg/L for Cu (0.651 mg/g); 2.52 mg/L for Pb (0.986 mg/g); 23.84 mg/L for Zn (1.616 mg/g). Percentage elution of trace metals from hair after treatment with metal-enriched solutions by five different procedures ranged from 14.5 to 46.5% for Al, from 11.1 to 28.9% for Zn, from 11.5 to 28.4% for Pb, from 8.9 to 13.6% for Cd, and from 0.1 to 11.8% for Cu. In addition, trace element concentrations were measured in tap water samples and shampoos.

Scalp hair as an indicator of aluminium exposure: comparison to bone and plasma.

1. Aluminium concentrations were measured in hair, plasma and bone samples from different groups of chronic renal insufficient patients and from a control group (75 healthy volunteers plus 21 deceased subjects). A cross-sectional study with 40 haemodialysis patients and two longitudinal studies were undertaken, the first comprising of 12 home haemodialysis patients and the second 16 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). 2. Before introduction of water treatment by reverse osmosis, the hair aluminium levels of home haemodialysis patients were elevated compared to controls. Aluminium in the hair of all other groups were within the normal range. Hair aluminium levels were not related to the daily aluminium intake, nor to the cumulative aluminium intake, nor to bone and plasma aluminium concentrations. 3. Plasma aluminium concentrations in all patients were higher than in the controls. Dialysis without reverse osmosis water treatment increased aluminium plasma levels. After installation of reverse osmosis units there was a decrease in the aluminium concentrations in plasma. In CAPD patients insignificant increases in the aluminium levels in plasma were observed. When low contaminated dialysis fluid was available the plasma aluminium concentrations returned to the initial level. 4. Aluminium concentrations in bone were increased in renal insufficient patients compared with controls. Aluminium bone content increased with increasing cumulative aluminium intake by phosphate binding therapy. 5. Hair analysis is of very limited value for the diagnosis of aluminium exposure. Bone analysis is suitable for the assessment of the individual body burden.

[Elimination of aluminum via continuous ambulatory peritoneal dialysis]. / Elimination von Aluminium bei kontinuierlicher ambulanter Peritonealdialyse.

Aluminum concentrations in the dialysate and serum of 14 patients on CAPD were measured every six months. Additionally, in ten of the patients Al elimination was measured after a bolus ingestion of 1800 mg aluminium-chloride-hydroxide-complex. There was no significant difference between serum Al concentrations initially (47.3 +/- 8.2 micrograms/l), at six months (55.4 +/- 9.5 micrograms/l), and after 12 months (44.3 +/- 10.1 micrograms/l) although the Al concentration in the dialysate had been decreased from 16.6 +/- 2.3 micrograms/l to 1.5 +/- 0.2 in the last six months. The Al concentrations in the effluent dialysate were 14.5 +/- 1.3 micrograms/l initially, 15.6 +/- 1.2 micrograms/l after six months and 11.9 +/- 2.6 micrograms/l after 12 months. During kinetic studies a constant rise of serum Al concentration was found until the fifth hour, from 29.9 +/- 2.5 to 42.5 +/- 4.0, and a decline after 24 hours to 32.4 +/- 3.0 micrograms/l. The quantity of Al eliminated was 41.1 +/- 8.7 micrograms/24 h, equivalent to 1.2% of the ingested dose. In patients with residual renal function, renal Al clearance was almost double the peritoneal one. These results indicate that Al elimination by CAPD is not efficient and ingestion of Al-containing phosphate binders can result in Al accumulation.

Hair zinc of young children from rural and urban areas in North Rhine-Westphalia, Federal Republic of Germany.

Hair zinc levels were estimated by atomic absorption spectrophotometry in 474 children, aged 3-7 years, from 11 kindergartens in a highly industrialized and polluted area (Duisburg) and 8 kindergartens in a rural area of North Rhine-Westphalia. The mean hair zinc level amounted to 118 micrograms/g, increasing between the 4th and 7th year of life. At all ages the values from the urban toddlers were lower than from rural toddlers, and in both regions they were higher in winter than in summer. Children with frequent upper respiratory tract infections (greater than 6 infections/year) showed significantly lower zinc hair values, independent of their age. Low hair zinc values (below 70 micrograms/g) were frequently found, raising the question as to whether this is a normal, age-related phenomenon, or whether it indicates a suboptimal zinc status of young children from North Rhine-Westphalia.

Elimination of absorbed aluminum in patients undergoing continuous ambulatory peritoneal dialysis.

Intestinal absorption of aluminum (Al) from the phosphate binder aluminum-hydroxide-chloride (PhosphonormR) and successive renal and peritoneal Al elimination were studied in 11 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Al was measured by atomic absorption spectrometry in serum, urine, and dialysis fluid. Al levels in serum of all patients increased in average from 28.6 micrograms/l immediately before to a peak level of 41.6 microgramsWl 4 h after intake of 342 mg Al. After 24 h serum Al (34.0 micrograms/l) was still increased. Elimination across the peritoneum increased from 5.6 micrograms Al during the first 4 h to peak levels of 12.9 micrograms between hour 8 and 12 and decreased to 8.1 micrograms during the last 12 h. The Al clearance of the peritoneum was 0.43 ml/min. In the 6 patients with residual diuresis the renal Al excretion was higher than the peritoneal removal (48.1 micrograms/24 h vs. 24.8 micrograms/24 h). The renal Al clearance amounted to 1.6 ml/min. Assuming a gastrointestinal absorption quotient of 0.1% it is concluded that Al removal by CAPD in patients receiving 342 mg Al/day is not sufficient to prevent Al accumulation. In patients with remaining diuresis, the renal Al elimination exceeds the Al removal by the peritoneum.